The issue they're talking about here is fairness, with immigration as a concrete example. Simple and clean. How you think that fairness should be administered

The issue they're talking about here is fairness, with immigration as a concrete example. Simple and clean. How you think that fairness should be administered is up to you. If you want to advocate for removing immigration rules for naturalizing foreign spouses in Japan, just say that. Regardless of immigration, marriage should be "altered" to give everyone the same rights. If that means getting rid of the legal concept of marriage entirely, so be it. I could be wrong, but I'm sensing some false advocacy here. It seems like you're using immigration as a red herring - don't "alter" marriage, alter immigration laws instead! How about both?